Mine does it when its cold and I start it,goes into high idol and sounds like it has a pulse.it stops after I start driving

 

I am using a Mopar fuel filter from the dealership. My wife's brother-in-law works for Chrysler as an instructor for the Cummins diesel. He has heard stories from the dealer mechanics about using non-Mopar (not including Fleetguard) filters that cause failures (turbos, injectors, etc.). I used to think a filter was a filter until a bought a diesel and was informed to stick with Mopar or Fleetguard. Not that I am advertising for them or the in-law is trying to sell them. I will have him look at my truck this weekend (expected to get in the low 20s).

After his diagnosis - I will likely switch to Fleetguard based on previous mention in this thread. Thanks.

FYI - I read another post and I may not be correct when I said 3rd cylinder idle problems occur with 03 to 04 models. I read it was occuring with 2nd generation trucks in this forum.

 

The truck idled somewhat rough and my wife's brother-in-law thinks it is injectors. He also stated to change the fuel filter since gelled fuel accumulates in the filter. He asked how many miles were on the truck (about 50k) and stated that new injectors are a possibility. In addition - he recommended using an additive such as Standyne (sp?) to help clean the injectors.

 

You guys should hear my truck this week. It was -20 F Sunday night. Kids like to unhook my cord from the timer in the garage so they can charge their John Deere Gator. When I start my truck it sounds like a top fueler. It sits outside unfortunatley. The 3 cyl. cold start is pretty cool along with white smoke. Once it idles for about 2 minutes it will smoothe out and rev to 1000 RPM and stay there until the clutch is pushed in. When it's cold but not too cold like -10 to 10 above F it will just idle right up to 1000 RPM and run smoothe.

 

mine idles rough and pulses so much even after fuel filters are changed. i run power services cetane boosta nd ant i gel and it still surges. As a mechanic i am aware that cummins on its ISX series or newer common rail engines they like to do the 3 cylinder warm up thing.

 

I guess like everything else - I will live with it until it breaks something. -20F is cold - I would sound loud too if I was left outside.

 

I believe the 3 cylinder idle is for 2nd gens only. Please correct me if I'm wrong.

 

My truck does the same thing at high idle and it doesent have to be very cold. 15-30. when i first start it, it idles fine till it goes to high idle than it runs rough its definatly not a surge from the grid heater definatly a miss or maybe 3 cyl. start up if the 3rd gens do it , other than that the truck runs great with no problems. i alternate between stanadyne and lucus evey tank and use the baldwin PF7977 fuel filter

 

^ Amen ^ ! Mine does it too!

 

Between me and my friends their are or have been 6 3rd gens.None of those in those temps or colder have ever done such.VZDUDE.Call a buddy at STAR and ask them?

 

I'll see what I can come up with! Like always...too many irons in the fire! I should have time tomorrow!

 

I'm also having the same problem, 91,000 miles. Dealer replaced fuel pressure limiting valve 2 days ago but it still does it. Also convinced that it has nothing to to with the grid heater. 2005 2500 Quad Cab

 

I know for SURE that it is NOT the grid heater Since my truck does it even after been driving it for awhile and pull in somewhere (store quick stop) and come back out it it will be sitting ther on high idle loaping brum brum brum brum brum untill I step on the brake or go pedel. so even after being warm err hot, it still does it. yesterday it was only 15 above but I noticed that its even been doing this this summer mostly Ive noticed though since its started getting colder... so I dunno what it is but it sounds Hot err hopped up ya know!!! kinda cool but I worry that its and injector or something...

 

Did you turn on high-idle, or did it come on automatically?

 

Mine does it too..

I'm also sure its not the grid heaters, they only cycle for a couple minutes after startup (and the voltage gauge will dip). The sound is like a cam lope like Alramr said in his original post. I believe it has something to do with the programming in the ECM because if I turn off high idle and hold at the same rpm with the accelerator it doesn't do it.